# Copyright (c) 2015 Ultimaker B.V.
# Uranium is released under the terms of the AGPLv3 or higher.

from . import Operation
from UM.Scene.SceneNode import SceneNode #To get the world transformation.
from UM.Math.Vector import Vector

##  Operation that scales a scene node, uniformly or non-uniformly.
class ScaleOperation(Operation.Operation):
    ##  Initialises the scale operation.
    #
    #   \param node The scene node to scale.
    #   \param scale A matrix to scale the node with. This matrix should only be
    #   non-zero on the diagonal.
    #   \param set_scale Whether to simply replace the old scale with the new
    #   one (True) or modify the old scale (False).
    #   \param add_scale Whether to add to the old scale (True) or multiply with
    #   it (False).
    #   \param relative_scale Whether to multiply the scale relative to the
    #   current scale (True) or simply multiply it with a constant (False).
    #   \param scale_around_point All coordinates are moved away from or towards
    #   this point.
    #   \param snap Whether to use snap scaling (True) or not (False).
    def __init__(self, node, scale, set_scale = False, add_scale = False, relative_scale = False, scale_around_point = Vector(0, 0, 0), snap = False):
        super().__init__()
        self._node = node #The scene node to scale.
        self._old_transformation = node.getLocalTransformation() #The transformation of the node before scaling.
        self._set_scale = set_scale #Whether to simply change the scale.
        self._add_scale = add_scale #Whether to add to the old scale.
        self._relative_scale = relative_scale #Whether to multiply relatively.
        self._scale_around_point = scale_around_point #The origin of the scale operation.
        self._snap = snap #Use snap scaling?
        self._scale = scale #The transformation matrix that scales space correctly.
        self._min_scale = 0.01 #A minimum scale factor. Much lower would introduce rounding errors.

    ##  Undo the scale operation.
    def undo(self):
        self._node.setTransformation(self._old_transformation)

    ##  Redo the scale operation.
    def redo(self):
        if self._set_scale: #Simply change the scale.
            self._node.setScale(self._scale, SceneNode.TransformSpace.World)
        elif self._add_scale: #Add to the current scale.
            self._node.setScale(self._node.getScale() + self._scale)
        elif self._relative_scale: #Scale relatively to the current scale.
            scale_factor = Vector()
            ## Ensure that the direction is correctly applied (it can be flipped due to mirror)
            if self._scale.z == self._scale.y and self._scale.y == self._scale.x:
                ratio = (1 / (self._node.getScale().x + self._node.getScale().y + self._node.getScale().z)) * 3
                ratio_vector = ratio * self._node.getScale()
                self._scale *= ratio_vector
            if self._node.getScale().x > 0:
                scale_factor = scale_factor.set(x=abs(self._node.getScale().x + self._scale.x))
            else:
                scale_factor = scale_factor.set(x=-abs(self._node.getScale().x - self._scale.x))
            if self._node.getScale().y > 0:
                scale_factor = scale_factor.set(y=abs(self._node.getScale().y + self._scale.y))
            else:
                scale_factor = scale_factor.set(y=-abs(self._node.getScale().y - self._scale.y))
            if self._node.getScale().z > 0:
                scale_factor = scale_factor.set(z=abs(self._node.getScale().z + self._scale.z))
            else:
                scale_factor = scale_factor.set(z=-abs(self._node.getScale().z - self._scale.z))

            current_scale = self._node.getScale()

            if scale_factor.x != 0:
                scale_factor = scale_factor.set(x=scale_factor.x / current_scale.x)
            if scale_factor.y != 0:
                scale_factor = scale_factor.set(y=scale_factor.y / current_scale.y)
            if scale_factor.z != 0:
                scale_factor = scale_factor.set(z=scale_factor.z / current_scale.z)

            self._node.setPosition(-self._scale_around_point) #If scaling around a point, shift that point to the axis origin first and shift it back after performing the transformation.
            self._node.scale(scale_factor, SceneNode.TransformSpace.Parent)
            self._node.setPosition(self._scale_around_point)
            new_scale = self._node.getScale()
            if self._snap:
                if scale_factor.x != 1.0:
                    new_scale = new_scale.set(x=round(new_scale.x, 2))
                if scale_factor.y != 1.0:
                    new_scale = new_scale.set(y=round(new_scale.y, 2))
                if scale_factor.z != 1.0 :
                    new_scale = new_scale.set(z=round(new_scale.z, 2))

            # Enforce min size.
            if new_scale.x < self._min_scale and new_scale.x >= 0:
                new_scale = new_scale.set(x=self._min_scale)
            if new_scale.y < self._min_scale and new_scale.y >= 0:
                new_scale = new_scale.set(y=self._min_scale)
            if new_scale.z < self._min_scale and new_scale.z >= 0:
                new_scale = new_scale.set(z=self._min_scale)

            # Enforce min size (when mirrored)
            if new_scale.x > -self._min_scale and new_scale.x <= 0:
                new_scale = new_scale.set(x=-self._min_scale)
            if new_scale.y > -self._min_scale and new_scale.y <= 0:
                new_scale = new_scale.set(y=-self._min_scale)
            if new_scale.z > -self._min_scale and new_scale.z <=0:
                new_scale = new_scale.set(z=-self._min_scale)
            self._node.setScale(new_scale, SceneNode.TransformSpace.World)
        else:
            self._node.setPosition(-self._scale_around_point, SceneNode.TransformSpace.World)  # If scaling around a point, shift that point to the axis origin first and shift it back after performing the transformation.
            self._node.scale(self._scale, SceneNode.TransformSpace.World) #Default to _set_scale
            self._node.setPosition(self._scale_around_point, SceneNode.TransformSpace.World)  # If scaling around a point, shift that point to the axis origin first and shift it back after performing the transformation.

    ##  Merge this operation with another scale operation.
    #
    #   This prevents the user from having to undo multiple operations if they
    #   were not his operations.
    #
    #   You should ONLY merge this operation with an older operation. It is NOT
    #   symmetric.
    #
    #   \param other The older scale operation to merge this operation with.
    #   \return A new operation that performs both scale operations.
    def mergeWith(self, other):
        if type(other) is not ScaleOperation:
            return False
        if other._node != self._node: #Must be scaling the same node.
            return False
        if other._set_scale and not self._set_scale: #Must be the same type of scaling.
            return False
        if other._add_scale and not self._add_scale:
            return False
        if other._relative_scale and not self._relative_scale:
            return False

        op = ScaleOperation(self._node, self._node.getScale())
        op._old_transformation = other._old_transformation #Use the oldest transformation of the two.
        return op

    ##  Returns a programmer-readable representation of this operation.
    #
    #   \return A programmer-readable representation of this operation.
    def __repr__(self):
        return "ScaleOperation(node = {0}, scale={1})".format(self._node, self._scale)

